diff options
Diffstat (limited to 'drivers/staging/hv/ring_buffer.c')
| -rw-r--r-- | drivers/staging/hv/ring_buffer.c | 526 |
1 files changed, 211 insertions, 315 deletions
diff --git a/drivers/staging/hv/ring_buffer.c b/drivers/staging/hv/ring_buffer.c index 66688fb69741..3da333018b5a 100644 --- a/drivers/staging/hv/ring_buffer.c +++ b/drivers/staging/hv/ring_buffer.c @@ -18,13 +18,16 @@ * Authors: * Haiyang Zhang <haiyangz@microsoft.com> * Hank Janssen <hjanssen@microsoft.com> + * K. Y. Srinivasan <kys@microsoft.com> * */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/kernel.h> #include <linux/mm.h> -#include "logging.h" -#include "ring_buffer.h" + +#include "hyperv.h" +#include "hyperv_vmbus.h" /* #defines */ @@ -34,18 +37,15 @@ #define BYTES_AVAIL_TO_WRITE(r, w, z) ((w) >= (r)) ? ((z) - ((w) - (r))) : ((r) - (w)) -/*++ - -Name: - get_ringbuffer_availbytes() - -Description: - Get number of bytes available to read and to write to - for the specified ring buffer - ---*/ +/* + * + * hv_get_ringbuffer_availbytes() + * + * Get number of bytes available to read and to write to + * for the specified ring buffer + */ static inline void -get_ringbuffer_availbytes(struct hv_ring_buffer_info *rbi, +hv_get_ringbuffer_availbytes(struct hv_ring_buffer_info *rbi, u32 *read, u32 *write) { u32 read_loc, write_loc; @@ -58,162 +58,131 @@ get_ringbuffer_availbytes(struct hv_ring_buffer_info *rbi, *read = rbi->ring_datasize - *write; } -/*++ - -Name: - get_next_write_location() - -Description: - Get the next write location for the specified ring buffer - ---*/ +/* + * hv_get_next_write_location() + * + * Get the next write location for the specified ring buffer + * + */ static inline u32 -get_next_write_location(struct hv_ring_buffer_info *ring_info) +hv_get_next_write_location(struct hv_ring_buffer_info *ring_info) { u32 next = ring_info->ring_buffer->write_index; - /* ASSERT(next < ring_info->RingDataSize); */ - return next; } -/*++ - -Name: - set_next_write_location() - -Description: - Set the next write location for the specified ring buffer - ---*/ +/* + * hv_set_next_write_location() + * + * Set the next write location for the specified ring buffer + * + */ static inline void -set_next_write_location(struct hv_ring_buffer_info *ring_info, +hv_set_next_write_location(struct hv_ring_buffer_info *ring_info, u32 next_write_location) { ring_info->ring_buffer->write_index = next_write_location; } -/*++ - -Name: - get_next_read_location() - -Description: - Get the next read location for the specified ring buffer - ---*/ +/* + * hv_get_next_read_location() + * + * Get the next read location for the specified ring buffer + */ static inline u32 -get_next_read_location(struct hv_ring_buffer_info *ring_info) +hv_get_next_read_location(struct hv_ring_buffer_info *ring_info) { u32 next = ring_info->ring_buffer->read_index; - /* ASSERT(next < ring_info->RingDataSize); */ - return next; } -/*++ - -Name: - get_next_readlocation_withoffset() - -Description: - Get the next read location + offset for the specified ring buffer. - This allows the caller to skip - ---*/ +/* + * hv_get_next_readlocation_withoffset() + * + * Get the next read location + offset for the specified ring buffer. + * This allows the caller to skip + */ static inline u32 -get_next_readlocation_withoffset(struct hv_ring_buffer_info *ring_info, +hv_get_next_readlocation_withoffset(struct hv_ring_buffer_info *ring_info, u32 offset) { u32 next = ring_info->ring_buffer->read_index; - /* ASSERT(next < ring_info->RingDataSize); */ next += offset; next %= ring_info->ring_datasize; return next; } -/*++ - -Name: - set_next_read_location() - -Description: - Set the next read location for the specified ring buffer - ---*/ +/* + * + * hv_set_next_read_location() + * + * Set the next read location for the specified ring buffer + * + */ static inline void -set_next_read_location(struct hv_ring_buffer_info *ring_info, +hv_set_next_read_location(struct hv_ring_buffer_info *ring_info, u32 next_read_location) { ring_info->ring_buffer->read_index = next_read_location; } -/*++ - -Name: - get_ring_buffer() - -Description: - Get the start of the ring buffer - ---*/ +/* + * + * hv_get_ring_buffer() + * + * Get the start of the ring buffer + */ static inline void * -get_ring_buffer(struct hv_ring_buffer_info *ring_info) +hv_get_ring_buffer(struct hv_ring_buffer_info *ring_info) { return (void *)ring_info->ring_buffer->buffer; } -/*++ - -Name: - get_ring_buffersize() - -Description: - Get the size of the ring buffer - ---*/ +/* + * + * hv_get_ring_buffersize() + * + * Get the size of the ring buffer + */ static inline u32 -get_ring_buffersize(struct hv_ring_buffer_info *ring_info) +hv_get_ring_buffersize(struct hv_ring_buffer_info *ring_info) { return ring_info->ring_datasize; } -/*++ - -Name: - get_ring_bufferindices() - -Description: - Get the read and write indices as u64 of the specified ring buffer - ---*/ +/* + * + * hv_get_ring_bufferindices() + * + * Get the read and write indices as u64 of the specified ring buffer + * + */ static inline u64 -get_ring_bufferindices(struct hv_ring_buffer_info *ring_info) +hv_get_ring_bufferindices(struct hv_ring_buffer_info *ring_info) { return (u64)ring_info->ring_buffer->write_index << 32; } -/*++ - -Name: - dump_ring_info() - -Description: - Dump out to console the ring buffer info - ---*/ -void dump_ring_info(struct hv_ring_buffer_info *ring_info, char *prefix) +/* + * + * hv_dump_ring_info() + * + * Dump out to console the ring buffer info + * + */ +void hv_dump_ring_info(struct hv_ring_buffer_info *ring_info, char *prefix) { u32 bytes_avail_towrite; u32 bytes_avail_toread; - get_ringbuffer_availbytes(ring_info, + hv_get_ringbuffer_availbytes(ring_info, &bytes_avail_toread, &bytes_avail_towrite); @@ -231,41 +200,90 @@ void dump_ring_info(struct hv_ring_buffer_info *ring_info, char *prefix) } -/* Internal routines */ - -static u32 -copyto_ringbuffer( - struct hv_ring_buffer_info *ring_info, - u32 start_write_offset, - void *src, - u32 srclen); - -static u32 -copyfrom_ringbuffer( +/* + * + * hv_copyfrom_ringbuffer() + * + * Helper routine to copy to source from ring buffer. + * Assume there is enough room. Handles wrap-around in src case only!! + * + */ +static u32 hv_copyfrom_ringbuffer( struct hv_ring_buffer_info *ring_info, void *dest, u32 destlen, - u32 start_read_offset); + u32 start_read_offset) +{ + void *ring_buffer = hv_get_ring_buffer(ring_info); + u32 ring_buffer_size = hv_get_ring_buffersize(ring_info); + u32 frag_len; + /* wrap-around detected at the src */ + if (destlen > ring_buffer_size - start_read_offset) { + frag_len = ring_buffer_size - start_read_offset; -/*++ + memcpy(dest, ring_buffer + start_read_offset, frag_len); + memcpy(dest + frag_len, ring_buffer, destlen - frag_len); + } else + + memcpy(dest, ring_buffer + start_read_offset, destlen); + + + start_read_offset += destlen; + start_read_offset %= ring_buffer_size; + + return start_read_offset; +} + + +/* + * + * hv_copyto_ringbuffer() + * + * Helper routine to copy from source to ring buffer. + * Assume there is enough room. Handles wrap-around in dest case only!! + * + */ +static u32 hv_copyto_ringbuffer( + struct hv_ring_buffer_info *ring_info, + u32 start_write_offset, + void *src, + u32 srclen) +{ + void *ring_buffer = hv_get_ring_buffer(ring_info); + u32 ring_buffer_size = hv_get_ring_buffersize(ring_info); + u32 frag_len; + + /* wrap-around detected! */ + if (srclen > ring_buffer_size - start_write_offset) { + frag_len = ring_buffer_size - start_write_offset; + memcpy(ring_buffer + start_write_offset, src, frag_len); + memcpy(ring_buffer, src + frag_len, srclen - frag_len); + } else + memcpy(ring_buffer + start_write_offset, src, srclen); -Name: - ringbuffer_get_debuginfo() + start_write_offset += srclen; + start_write_offset %= ring_buffer_size; -Description: - Get various debug metrics for the specified ring buffer + return start_write_offset; +} ---*/ -void ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info, +/* + * + * hv_ringbuffer_get_debuginfo() + * + * Get various debug metrics for the specified ring buffer + * + */ +void hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info, struct hv_ring_buffer_debug_info *debug_info) { u32 bytes_avail_towrite; u32 bytes_avail_toread; if (ring_info->ring_buffer) { - get_ringbuffer_availbytes(ring_info, + hv_get_ringbuffer_availbytes(ring_info, &bytes_avail_toread, &bytes_avail_towrite); @@ -281,30 +299,26 @@ void ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info, } -/*++ - -Name: - get_ringbuffer_interrupt_mask() - -Description: - Get the interrupt mask for the specified ring buffer - ---*/ -u32 get_ringbuffer_interrupt_mask(struct hv_ring_buffer_info *rbi) +/* + * + * hv_get_ringbuffer_interrupt_mask() + * + * Get the interrupt mask for the specified ring buffer + * + */ +u32 hv_get_ringbuffer_interrupt_mask(struct hv_ring_buffer_info *rbi) { return rbi->ring_buffer->interrupt_mask; } -/*++ - -Name: - ringbuffer_init() - -Description: - Initialize the ring buffer - ---*/ -int ringbuffer_init(struct hv_ring_buffer_info *ring_info, +/* + * + * hv_ringbuffer_init() + * + *Initialize the ring buffer + * + */ +int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info, void *buffer, u32 buflen) { if (sizeof(struct hv_ring_buffer) != PAGE_SIZE) @@ -324,29 +338,25 @@ int ringbuffer_init(struct hv_ring_buffer_info *ring_info, return 0; } -/*++ - -Name: - ringbuffer_cleanup() - -Description: - Cleanup the ring buffer - ---*/ -void ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info) +/* + * + * hv_ringbuffer_cleanup() + * + * Cleanup the ring buffer + * + */ +void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info) { } -/*++ - -Name: - ringbuffer_write() - -Description: - Write to the ring buffer - ---*/ -int ringbuffer_write(struct hv_ring_buffer_info *outring_info, +/* + * + * hv_ringbuffer_write() + * + * Write to the ring buffer + * + */ +int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info, struct scatterlist *sglist, u32 sgcount) { int i = 0; @@ -355,7 +365,7 @@ int ringbuffer_write(struct hv_ring_buffer_info *outring_info, u32 totalbytes_towrite = 0; struct scatterlist *sg; - volatile u32 next_write_location; + u32 next_write_location; u64 prev_indices = 0; unsigned long flags; @@ -368,43 +378,34 @@ int ringbuffer_write(struct hv_ring_buffer_info *outring_info, spin_lock_irqsave(&outring_info->ring_lock, flags); - get_ringbuffer_availbytes(outring_info, + hv_get_ringbuffer_availbytes(outring_info, &bytes_avail_toread, &bytes_avail_towrite); - DPRINT_DBG(VMBUS, "Writing %u bytes...", totalbytes_towrite); - - /* Dumpring_info(Outring_info, "BEFORE "); */ /* If there is only room for the packet, assume it is full. */ /* Otherwise, the next time around, we think the ring buffer */ /* is empty since the read index == write index */ if (bytes_avail_towrite <= totalbytes_towrite) { - DPRINT_DBG(VMBUS, - "No more space left on outbound ring buffer " - "(needed %u, avail %u)", - totalbytes_towrite, - bytes_avail_towrite); - spin_unlock_irqrestore(&outring_info->ring_lock, flags); return -1; } /* Write to the ring buffer */ - next_write_location = get_next_write_location(outring_info); + next_write_location = hv_get_next_write_location(outring_info); for_each_sg(sglist, sg, sgcount, i) { - next_write_location = copyto_ringbuffer(outring_info, + next_write_location = hv_copyto_ringbuffer(outring_info, next_write_location, sg_virt(sg), sg->length); } /* Set previous packet start */ - prev_indices = get_ring_bufferindices(outring_info); + prev_indices = hv_get_ring_bufferindices(outring_info); - next_write_location = copyto_ringbuffer(outring_info, + next_write_location = hv_copyto_ringbuffer(outring_info, next_write_location, &prev_indices, sizeof(u64)); @@ -413,25 +414,22 @@ int ringbuffer_write(struct hv_ring_buffer_info *outring_info, mb(); /* Now, update the write location */ - set_next_write_location(outring_info, next_write_location); + hv_set_next_write_location(outring_info, next_write_location); - /* Dumpring_info(Outring_info, "AFTER "); */ spin_unlock_irqrestore(&outring_info->ring_lock, flags); return 0; } -/*++ - -Name: - ringbuffer_peek() - -Description: - Read without advancing the read index - ---*/ -int ringbuffer_peek(struct hv_ring_buffer_info *Inring_info, +/* + * + * hv_ringbuffer_peek() + * + * Read without advancing the read index + * + */ +int hv_ringbuffer_peek(struct hv_ring_buffer_info *Inring_info, void *Buffer, u32 buflen) { u32 bytes_avail_towrite; @@ -441,17 +439,12 @@ int ringbuffer_peek(struct hv_ring_buffer_info *Inring_info, spin_lock_irqsave(&Inring_info->ring_lock, flags); - get_ringbuffer_availbytes(Inring_info, + hv_get_ringbuffer_availbytes(Inring_info, &bytes_avail_toread, &bytes_avail_towrite); /* Make sure there is something to read */ if (bytes_avail_toread < buflen) { - /* DPRINT_DBG(VMBUS, - "got callback but not enough to read " - "<avail to read %d read size %d>!!", - bytes_avail_toread, - BufferLen); */ spin_unlock_irqrestore(&Inring_info->ring_lock, flags); @@ -459,9 +452,9 @@ int ringbuffer_peek(struct hv_ring_buffer_info *Inring_info, } /* Convert to byte offset */ - next_read_location = get_next_read_location(Inring_info); + next_read_location = hv_get_next_read_location(Inring_info); - next_read_location = copyfrom_ringbuffer(Inring_info, + next_read_location = hv_copyfrom_ringbuffer(Inring_info, Buffer, buflen, next_read_location); @@ -472,16 +465,14 @@ int ringbuffer_peek(struct hv_ring_buffer_info *Inring_info, } -/*++ - -Name: - ringbuffer_read() - -Description: - Read and advance the read index - ---*/ -int ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer, +/* + * + * hv_ringbuffer_read() + * + * Read and advance the read index + * + */ +int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer, u32 buflen, u32 offset) { u32 bytes_avail_towrite; @@ -495,36 +486,26 @@ int ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer, spin_lock_irqsave(&inring_info->ring_lock, flags); - get_ringbuffer_availbytes(inring_info, + hv_get_ringbuffer_availbytes(inring_info, &bytes_avail_toread, &bytes_avail_towrite); - DPRINT_DBG(VMBUS, "Reading %u bytes...", buflen); - - /* Dumpring_info(Inring_info, "BEFORE "); */ - /* Make sure there is something to read */ if (bytes_avail_toread < buflen) { - DPRINT_DBG(VMBUS, - "got callback but not enough to read " - "<avail to read %d read size %d>!!", - bytes_avail_toread, - buflen); - spin_unlock_irqrestore(&inring_info->ring_lock, flags); return -1; } next_read_location = - get_next_readlocation_withoffset(inring_info, offset); + hv_get_next_readlocation_withoffset(inring_info, offset); - next_read_location = copyfrom_ringbuffer(inring_info, + next_read_location = hv_copyfrom_ringbuffer(inring_info, buffer, buflen, next_read_location); - next_read_location = copyfrom_ringbuffer(inring_info, + next_read_location = hv_copyfrom_ringbuffer(inring_info, &prev_indices, sizeof(u64), next_read_location); @@ -535,94 +516,9 @@ int ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer, mb(); /* Update the read index */ - set_next_read_location(inring_info, next_read_location); - - /* Dumpring_info(Inring_info, "AFTER "); */ + hv_set_next_read_location(inring_info, next_read_location); spin_unlock_irqrestore(&inring_info->ring_lock, flags); return 0; } - - -/*++ - -Name: - copyto_ringbuffer() - -Description: - Helper routine to copy from source to ring buffer. - Assume there is enough room. Handles wrap-around in dest case only!! - ---*/ -static u32 -copyto_ringbuffer( - struct hv_ring_buffer_info *ring_info, - u32 start_write_offset, - void *src, - u32 srclen) -{ - void *ring_buffer = get_ring_buffer(ring_info); - u32 ring_buffer_size = get_ring_buffersize(ring_info); - u32 frag_len; - - /* wrap-around detected! */ - if (srclen > ring_buffer_size - start_write_offset) { - DPRINT_DBG(VMBUS, "wrap-around detected!"); - - frag_len = ring_buffer_size - start_write_offset; - memcpy(ring_buffer + start_write_offset, src, frag_len); - memcpy(ring_buffer, src + frag_len, srclen - frag_len); - } else - memcpy(ring_buffer + start_write_offset, src, srclen); - - start_write_offset += srclen; - start_write_offset %= ring_buffer_size; - - return start_write_offset; -} - - -/*++ - -Name: - copyfrom_ringbuffer() - -Description: - Helper routine to copy to source from ring buffer. - Assume there is enough room. Handles wrap-around in src case only!! - ---*/ -static u32 -copyfrom_ringbuffer( - struct hv_ring_buffer_info *ring_info, - void *dest, - u32 destlen, - u32 start_read_offset) -{ - void *ring_buffer = get_ring_buffer(ring_info); - u32 ring_buffer_size = get_ring_buffersize(ring_info); - - u32 frag_len; - - /* wrap-around detected at the src */ - if (destlen > ring_buffer_size - start_read_offset) { - DPRINT_DBG(VMBUS, "src wrap-around detected!"); - - frag_len = ring_buffer_size - start_read_offset; - - memcpy(dest, ring_buffer + start_read_offset, frag_len); - memcpy(dest + frag_len, ring_buffer, destlen - frag_len); - } else - - memcpy(dest, ring_buffer + start_read_offset, destlen); - - - start_read_offset += destlen; - start_read_offset %= ring_buffer_size; - - return start_read_offset; -} - - -/* eof */ |